In the Philippines, the first trial of men suspected of massacring 57 people has begun.

Lakmudin Saliao says for eight years he was a personal assistant to Andal Ampatuan Senior, the head of a powerful clan in the southern Philippine province of Maguindanao.

He testified in court Wednesday that he helped coordinate several conferences in which his boss's son, Andal Ampatuan Junior, suggested and planned the murder of a political rival and his supporters.

Saliao says the younger Ampatuan planned to intercept Emanuel Mangudadatu on his way to register as candidate for governor of Maguindanao. But Mangudadatu did not file the papers. Instead his wife and sister - accompanied by more than 50 supporters and journalists - went and were killed last November.

Ampatuan has pleaded not guilty to the murder charges, and the family has denied the allegations.

Saliao says Andal Ampatuan Senior tried to work out a deal to have his son surrender to the care of then President Gloria Macapagal Arroyo.

Harry Roque, an attorney for the families of several of those killed, says prosecutors are trying to subpoena Mrs. Arroyo.

"We want to know, why? Because normal accused are not sent to the president," he explained. "They are sent to the police."

The Ampatuans were political allies of Mrs. Arroyo.

The killing of political rivals is nothing new in the Philippines, a country where some provincial leaders and wealthy families maintain private militias. The Philippines also suffers from both a communist insurgency and a Muslim separatist movement in the south. And for years, journalists investigating corruption, labor activists and human rights workers have been threatened and killed; in most cases, no one is ever arrested for the crimes.

The families of the massacre victims and rights activists welcomed the start of the trial.

Jessica Evans, an Asia fellow with Human Rights Watch, says, "At the same time we are only three hours into the first witness in a trial that involves only 19 of the 195 accused, so we have a very long road ahead."

Nearly 200 people have been charged with taking part in the killings, but more than half are at large. Evans says that puts witnesses at risk of being intimidated to keep them from testifying.

Because of the number of suspects, and the list of more than 200 witnesses expected to testify, the trial could drag on for months.